#include <REGX52.H>
	void Delay1ms(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;
		while(xms--)
		{ i = 2;
			j = 239;
			do
			{
				while (--j);
			} while (--i);
		}
}

	
	void main()
	{
		while(1)
		{
			if(P3_1==0)
			{
				Delay1ms(20);
			  while(P3_1==0);
				Delay1ms(20);
				P2_0=~P2_0;
			
			}
		
		
		}
	
	
	}